Enum oxygengine_core::ecs::storage::StorageEntry

pub enum StorageEntry<'a, 'b, T, D> where
    'b: 'a,
    D: 'a,
    T: 'a,  {
    Occupied(OccupiedEntry<'a, 'b, T, D>),
    Vacant(VacantEntry<'a, 'b, T, D>),
}

Entry to a storage for convenient filling of components or removal based on whether the entity has a component.

Variants

Occupied(OccupiedEntry<'a, 'b, T, D>)

Entry variant that is returned if the entity has a component.

Vacant(VacantEntry<'a, 'b, T, D>)

Entry variant that is returned if the entity does not have a component.

Implementations

impl<'a, 'b, T, D> StorageEntry<'a, 'b, T, D> where
    D: DerefMut<Target = MaskedStorage<T>>,
    T: Component, 

pub fn replace(self, component: T) -> Option<T>

Inserts a component and returns the old value in case this entry was already occupied.

pub fn or_insert(self, component: T) -> &'a mut T

Inserts a component if the entity does not have it already.

pub fn or_insert_with<F>(self, default: F) -> &'a mut T where
    F: FnOnce() -> T, 

Inserts a component using a lazily called function that is only called when inserting the component. Ensures this entry has a value and if not, inserts one using the result of the passed closure. Returns a reference to the value afterwards.